The present invention is concerned with the monitoring of multiple channel solenoid currents particularly, but not exclusively, in automotive electrical and electronic control systems.
There are many situations in electrical and electronic control systems where there is a requirement for the current flowing in a solenoid coil to be monitored and measured. Conventionally, each channel containing an individual solenoid coil has its own current sensing element associated with it Usually, the sensing element comprises a resistive element, eg. a simple resistor disposed in series with the solenoid coil, whereby the voltage drop across the resistor is proportional to the current flowing through it, and hence proportional to the current flowing through the solenoid coil. The voltage across the resistor is conditioned and read by an analogue to digital converter (ADC).
The known arrangement thus has the associated cost disadvantage that individual sensing elements and conditioning are required for each channel of current to be measured, ie. for each solenoid coil to be monitored.
It would be advantageous to provide, particularly for automotive applications, an arrangement whereby it is no longer necessary for there to be individual sensing elements for each solenoid channel.